BEST OVERALL: YoLink LoRa Smart Window Door Sensors. ↓ Jump to Review. BEST BANG FOR THE BUCK: GE Personal Security Window and Door Alarm. ↓ Jump to Review. UPGRADE PICK: Ring Alarm 5-Piece ...

Door Locks, Personal Alarms, Portable Safes, And Other Products That Will Come In Handy If You’re An Anxious Traveler. 5mo. 1. An anti-theft sock if you want to keep your cash close, but ...

If the freezer door is open, the reed switch similarly remains open. The ESP32 checks the switch status every few minutes, and if the door remains open for two consecutive checks, it raises the alarm.

This article was originally published with the title “ Detonating Door and Window Alarm ” in Scientific American Magazine Vol. 8 No. 8 (November 1852), p. 60 doi:10.1038 ...